The county began taking formation on November 14, 1788 under authorization of the Virginia General Assembly, and was founded on October 5, 1789. The county was named for the Kanawha River, which in turn was named after the Indian tribe that lived in the area.[3] The county was the site of a major Textbook controversy in 1974 that included bombings and received national attention.

There were 86,226 households out of which 26.50% had children under the age of 18 living with them, 49.00% were married couples living together, 12.30% had a female householder with no husband present, and 35.10% were non-families. 30.80% of all households were made up of individuals and 12.50% had someone living alone who was 65 years of age or older. The average household size was 2.28 and the average family size was 2.84.

The age distribution was 21.30% under the age of 18, 8.40% from 18 to 24, 28.10% from 25 to 44, 25.60% from 45 to 64, and 16.50% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 90.70 males. For every 100 females age 18 and over, there were 87.10 males.

The median income for a household in the county was $33,766, and the median income for a family was $42,568. Males had a median income of $33,842 versus $24,188 for females. The per capita income for the county was $20,354. About 11.20% of families and 14.40% of the population were below the poverty line, including 20.60% of those under age 18 and 10.50% of those age 65 or over.

According to the 2010 U.S. Census there are approximately 5,481 private sector businesses within Kanawha County. There are 89,768 people that are currently employed that live in Kanawha County.[10] The most notable businesses throughout Kanawha County; Tech Park in South Charleston, Gestamp in South Charleston, Mardi Gras Casino, Chesapeake Energy in Charleston, Walker Machinery in Belle, Charleston Area Medical Center throughout Charleston, Thomas Memorial Hospital in South Charleston, Saint Francis Hospital in Charleston, C&O Motors in Saint Albans, Bert Wolf Ford in Charleston, Smith Motor Company in Charleston, and Joe Holland Chevrolet in South Charleston to name a few. Kanawha County also well known for many businesses in the chemical industry with presence from Dow Chemical Company, Clearon Corporation, and FMC Corporation all located in South Charleston and DuPont in Belle.